*x86: Support x2apic mode

Implement x2apic mode as existing code only supports apic mode.
Use info from LAPIC_BASE_MSR (LAPIC_BASE_MSR_X2APIC_MODE) to check
if apic mode or x2apic mode and implement x2apic mode according to
x2apic specfication.

Reference:
https://software.intel.com/content/www/us/en/develop/download/intel-64-architecture-x2apic-specification.html

BUG=None
BRANCH=None
TEST=boot to OS and check apic mode
cat /proc/cpuinfo | grep "apicid"
ex) can see apicid bigger than 255
apicid          : 256
apicid          : 260

Signed-off-by: Wonkyu Kim <wonkyu.kim@intel.com>
Change-Id: I0bb729b0521fb9dc38b7981014755daeaf9ca817
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51723
Reviewed-by: Ravishankar Sarawadi <ravishankar.sarawadi@intel.com>
Reviewed-by: Jamie Ryu <jamie.m.ryu@intel.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

7 files changed, 110 insertions, 24 deletions

diff --git a/src/arch/x86/cpu.c b/src/arch/x86/cpu.c
index 3ef878f517..07bd7b5ff2 100644
--- a/src/arch/x86/cpu.c
+++ b/src/arch/x86/cpu.c
@@ -213,17 +213,6 @@ static void set_cpu_ops(struct device *cpu)
 /* Keep track of default APIC ids for SMM. */
 static int cpus_default_apic_id[CONFIG_MAX_CPUS];
 
-/*
- * When CPUID executes with EAX set to 1, additional processor identification
- * information is returned to EBX register:
- * Default APIC ID: EBX[31-24] - this number is the 8 bit ID that is assigned
- * to the local APIC on the processor during power on.
- */
-static int initial_lapicid(void)
-{
-	return cpuid_ebx(1) >> 24;
-}
-
 /* Function to keep track of cpu default apic_id */
 void cpu_add_map_entry(unsigned int index)
 {
diff --git a/src/cpu/x86/lapic/lapic.c b/src/cpu/x86/lapic/lapic.c
index 988d664c94..a5b4cd5047 100644
--- a/src/cpu/x86/lapic/lapic.c
+++ b/src/cpu/x86/lapic/lapic.c
@@ -47,6 +47,6 @@ void lapic_virtual_wire_mode_init(void)
 			LAPIC_DELIVERY_MODE_NMI)
 		);
 
-	printk(BIOS_DEBUG, " apic_id: 0x%02x ", lapicid());
+	printk(BIOS_DEBUG, " apic_id: 0x%x ", lapicid());
 	printk(BIOS_INFO, "done.\n");
 }
diff --git a/src/cpu/x86/mp_init.c b/src/cpu/x86/mp_init.c
index 94a8fd8d8b..76f2650330 100644
--- a/src/cpu/x86/mp_init.c
+++ b/src/cpu/x86/mp_init.c
@@ -435,6 +435,28 @@ static int start_aps(struct bus *cpu_bus, int ap_count, atomic_t *num_aps)
 
 	printk(BIOS_DEBUG, "Attempting to start %d APs\n", ap_count);
 
+	if (is_x2apic_mode()) {
+		x2apic_send_ipi(LAPIC_DM_INIT | LAPIC_INT_LEVELTRIG |
+			LAPIC_INT_ASSERT | LAPIC_DEST_ALLBUT, 0);
+		mdelay(10);
+		x2apic_send_ipi(LAPIC_DM_STARTUP | LAPIC_INT_LEVELTRIG |
+			LAPIC_DEST_ALLBUT | sipi_vector, 0);
+
+		/* Wait for CPUs to check in up to 200 us. */
+		wait_for_aps(num_aps, ap_count, 200 /* us */, 15 /* us */);
+
+		x2apic_send_ipi(LAPIC_DM_STARTUP | LAPIC_INT_LEVELTRIG |
+			LAPIC_DEST_ALLBUT | sipi_vector, 0);
+
+		/* Wait for CPUs to check in. */
+		if (wait_for_aps(num_aps, ap_count, 100000 /* 100 ms */, 50 /* us */)) {
+			printk(BIOS_ERR, "Not all APs checked in: %d/%d.\n",
+			       atomic_read(num_aps), ap_count);
+			return -1;
+		}
+		return 0;
+	}
+
 	if ((lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY)) {
 		printk(BIOS_DEBUG, "Waiting for ICR not to be busy...");
 		if (apic_wait_timeout(1000 /* 1 ms */, 50)) {
@@ -653,6 +675,11 @@ static void mp_initialize_cpu(void)
 
 void smm_initiate_relocation_parallel(void)
 {
+	if (is_x2apic_mode()) {
+		x2apic_send_ipi(LAPIC_DM_SMI | LAPIC_INT_LEVELTRIG, lapicid());
+		return;
+	}
+
 	if ((lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY)) {
 		printk(BIOS_DEBUG, "Waiting for ICR not to be busy...");
 		if (apic_wait_timeout(1000 /* 1 ms */, 50)) {
diff --git a/src/cpu/x86/smm/smm_stub.S b/src/cpu/x86/smm/smm_stub.S
index 7c09e04108..f479d62536 100644
--- a/src/cpu/x86/smm/smm_stub.S
+++ b/src/cpu/x86/smm/smm_stub.S
@@ -11,6 +11,7 @@
 
 #include <cpu/x86/cr.h>
 #include <cpu/x86/msr.h>
+#include <cpu/x86/lapic_def.h>
 
 .code32
 .section ".module_parameters", "aw", @progbits
@@ -29,7 +30,7 @@ fxsave_area_size:
  * APIC id is found at the given index, the contiguous CPU number is index
  * into the table. */
 apic_to_cpu_num:
-.fill CONFIG_MAX_CPUS,1,0xff
+.fill CONFIG_MAX_CPUS,2,0xffff
 /* allows the STM to bring up SMM in 32-bit mode */
 start32_offset:
 .long smm_trampoline32 - _start
@@ -97,16 +98,31 @@ smm_trampoline32:
 
 	/* The CPU number is calculated by reading the initial APIC id. Since
 	 * the OS can maniuplate the APIC id use the non-changing cpuid result
-	 * for APIC id (ebx[31:24]). A table is used to handle a discontiguous
+	 * for APIC id (ax). A table is used to handle a discontiguous
 	 * APIC id space.  */
-	mov	$1, %eax
-	cpuid
-	bswap	%ebx	/* Default APIC id in bl. */
-	mov	$(apic_to_cpu_num), %eax
-	xor	%ecx, %ecx
+apic_id:
+        mov $LAPIC_BASE_MSR, %ecx
+        rdmsr
+        andl $LAPIC_BASE_MSR_X2APIC_MODE, %eax
+        jz xapic
+
+x2apic:
+        mov $X2APIC_LAPIC_ID, %ecx
+        rdmsr
+        jmp apicid_end
+
+xapic:
+        movl    $(LOCAL_APIC_ADDR | LAPIC_ID), %esi
+        movl    (%esi), %eax
+        shr     $24, %eax
+
+apicid_end:
+
+        mov     $(apic_to_cpu_num), %ebx
+        xor     %ecx, %ecx
 
 1:
-	cmp	(%eax, %ecx, 1), %bl
+	cmp	(%ebx, %ecx, 2), %ax
 	je	1f
 	inc	%ecx
 	cmp	$CONFIG_MAX_CPUS, %ecx
diff --git a/src/include/cpu/x86/lapic.h b/src/include/cpu/x86/lapic.h
index f4291ab35b..e2ca297659 100644
--- a/src/include/cpu/x86/lapic.h
+++ b/src/include/cpu/x86/lapic.h
@@ -2,19 +2,54 @@
 #define CPU_X86_LAPIC_H
 
 #include <arch/mmio.h>
+#include <arch/cpu.h>
 #include <cpu/x86/lapic_def.h>
 #include <cpu/x86/msr.h>
 #include <halt.h>
 #include <stdint.h>
 
+static inline bool is_x2apic_mode(void)
+{
+	msr_t msr;
+	msr = rdmsr(LAPIC_BASE_MSR);
+	return (msr.lo & LAPIC_BASE_MSR_X2APIC_MODE);
+}
+
+static inline void x2apic_send_ipi(uint32_t icrlow, uint32_t apicid)
+{
+	msr_t icr;
+	icr.hi = apicid;
+	icr.lo = icrlow;
+	wrmsr(X2APIC_MSR_ICR_ADDRESS, icr);
+}
+
 static __always_inline uint32_t lapic_read(unsigned int reg)
 {
-	return read32((volatile void *)(uintptr_t)(LAPIC_DEFAULT_BASE + reg));
+	uint32_t value, index;
+	msr_t msr;
+
+	if (is_x2apic_mode()) {
+		index = X2APIC_MSR_BASE_ADDRESS + (uint32_t)(reg >> 4);
+		msr = rdmsr(index);
+		value = msr.lo;
+	} else {
+		value = read32((volatile void *)(uintptr_t)(LAPIC_DEFAULT_BASE + reg));
+	}
+	return value;
 }
 
 static __always_inline void lapic_write(unsigned int reg, uint32_t v)
 {
-	write32((volatile void *)(uintptr_t)(LAPIC_DEFAULT_BASE + reg), v);
+	msr_t msr;
+	uint32_t index;
+	if (is_x2apic_mode()) {
+		index = X2APIC_MSR_BASE_ADDRESS + (uint32_t)(reg >> 4);
+		msr.hi = 0x0;
+		msr.lo = v;
+		wrmsr(index, msr);
+	} else {
+		write32((volatile void *)(uintptr_t)(LAPIC_DEFAULT_BASE + reg), v);
+	}
 }
 
 static __always_inline void lapic_wait_icr_idle(void)
@@ -41,9 +76,24 @@ static inline void disable_lapic(void)
 	wrmsr(LAPIC_BASE_MSR, msr);
 }
 
+static __always_inline unsigned int initial_lapicid(void)
+{
+	uint32_t lapicid;
+	if (is_x2apic_mode())
+		lapicid = lapic_read(LAPIC_ID);
+	else
+		lapicid = cpuid_ebx(1) >> 24;
+	return lapicid;
+}
+
 static __always_inline unsigned int lapicid(void)
 {
-	return lapic_read(LAPIC_ID) >> 24;
+	uint32_t lapicid = lapic_read(LAPIC_ID);
+
+	/* check x2apic mode and return accordingly */
+	if (!is_x2apic_mode())
+		lapicid >>= 24;
+	return lapicid;
 }
 
 #if !CONFIG(AP_IN_SIPI_WAIT)
diff --git a/src/include/cpu/x86/lapic_def.h b/src/include/cpu/x86/lapic_def.h
index 9da89ee873..5b25e5a968 100644
--- a/src/include/cpu/x86/lapic_def.h
+++ b/src/include/cpu/x86/lapic_def.h
@@ -3,6 +3,7 @@
 
 #define LAPIC_BASE_MSR 0x1B
 #define LAPIC_BASE_MSR_BOOTSTRAP_PROCESSOR (1 << 8)
+#define LAPIC_BASE_MSR_X2APIC_MODE (1 << 10)
 #define LAPIC_BASE_MSR_ENABLE (1 << 11)
 #define LAPIC_BASE_MSR_ADDR_MASK 0xFFFFF000
 
@@ -94,4 +95,7 @@
 #define		LAPIC_TDR_DIV_64		0x9
 #define		LAPIC_TDR_DIV_128	0xA
 
+#define X2APIC_MSR_BASE_ADDRESS	0x800
+#define X2APIC_LAPIC_ID		(X2APIC_MSR_BASE_ADDRESS | (LAPIC_ID >> 4))
+#define	X2APIC_MSR_ICR_ADDRESS	0x830
 #endif /* CPU_X86_LAPIC_DEF_H */
diff --git a/src/include/cpu/x86/smm.h b/src/include/cpu/x86/smm.h
index b42f3faef4..c42eb8cf7f 100644
--- a/src/include/cpu/x86/smm.h
+++ b/src/include/cpu/x86/smm.h
@@ -85,7 +85,7 @@ struct smm_stub_params {
 	 * initializes this array with a 1:1 mapping. If the APIC ids are not
 	 * contiguous like the 1:1 mapping it is up to the caller of the stub
 	 * loader to adjust this mapping. */
-	u8 apic_id_to_cpu[CONFIG_MAX_CPUS];
+	u16 apic_id_to_cpu[CONFIG_MAX_CPUS];
 	/* STM's 32bit entry into SMI handler */
 	u32 start32_offset;
 } __packed;